JPH0614907B2 - Biological signal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a biological signal display device for displaying biological signals such as an electrocardiogram signal and an electrocardiogram signal.

(B) Prior Art A conventional biological signal display device of this type is shown in FIG. That is, in this biological signal display device 1a, the biological signal S output from the biological signal detection circuit 2 is A / D converted by the successive A / D converter 6 according to the timing signal Z ₁ given from the timing signal generation circuit 4. . The digitized biomedical signal S is stored in a predetermined address position of the memory circuit 10a based on the address designation signal X from the write / read control circuit 8. The biological signal S stored here is sequentially read by the addressing signal X synchronized with the TV sync signal output from the TV sync signal generation circuit 12,
It is sent to the comparison circuit 14a at the next stage. The comparison circuit 14a compares the quantized level of the input biological signal S with the count value Y of the counter 16 based on the TV sync signal output of the TV sync signal generation circuit 12, and when both are equal, the display signal of the next stage is displayed. Output to the one-shot circuit 18. As a result, the one-shot circuit 18 outputs a bright spot signal, and the bright spot signal is given by T from the TV sync signal generating circuit 12.
The V sync signal is added by the adder 20 and output to the TV monitor 22.

By the way, the biological signal S obtained by the biological signal detection circuit 2 is obtained.
Is a signal having a relatively low frequency with one cycle of about 1 second. On the other hand, the storage capacity of the storage circuit 10a is set to about 500 bytes due to cost restrictions and the like. Due to these factors, in the conventional device 1a, the timing signal generation circuit 4
The timing signal Z ₁ given to the A / D converter 6 is set to a low frequency that matches the biological signal S, and the sampling rate of the biological signal S is set by this. Therefore, if it is attempted to store the biological signal S for 10 seconds in the memory circuit 10a, the sampling rate of the biological signal S that is A / D converted will be 15 to 30 milliseconds. The R wave of the electrocardiogram usually has a cycle interval of about 50 milliseconds, so when the biomedical signal is digitized at the above sampling rate, it becomes a discontinuous curve as shown in FIG. Instead of dropping the signal. Therefore, there is a problem that waveforms are displayed differently when the biological signal is sampled at the peak position and when it is not sampled, resulting in insufficient reproducibility.

(C) Object The present invention solves the above-mentioned problems of the related art, and makes it possible to display a biomedical signal as faithfully as possible in a continuous and easy-to-read manner, and to realize this at low cost.

(D) Structure In order to achieve such an object, the present invention provides an electrocardiogram signal,
A sampling signal generation circuit for giving a sampling signal having a frequency sufficiently larger than the frequency component of the biological signal to an A / D converter to which a biological signal such as a heart sound signal is input, and a digital signal by the A / D converter. Detector for detecting the maximum value and the minimum value of the quantization level included in the predetermined period of the digitized biomedical signal, and a storage circuit for storing each signal of the maximum value and the minimum value detected by this detector, , The quantization level of each signal of the maximum value and the minimum value read from the storage circuit is compared with the count value corresponding to the TV scanning line, and this count value is compared with the signal level of the maximum value and the minimum value. A comparison circuit that outputs a display signal when it is within the range of the quantization level, and a one-shot circuit that converts the display signal into a bright spot signal having an arbitrary pulse width are provided. So that the biosignal can be continuously displayed by interpolating between the signal values.

(E) Example Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 2 is a block diagram of the biological signal display device of this embodiment, and the portions corresponding to those in FIG. 1 are designated by the same reference numerals. In the figure, reference numeral 1b indicates a biological signal display device, reference numeral 2 indicates a biological signal detection circuit for outputting a biological signal S such as an electrocardiogram signal ECG and a heart sound signal, and 4 indicates a timing signal Z having a constant frequency.
₁ is a timing signal generating circuit, 24 is a sampling signal generating circuit which outputs a sampling signal Z ₂ having a frequency sufficiently larger than the frequency component of the biological signal S in response to the timing signal Z ₁ from the timing signal generating circuit 4. Circuit. 6 is a biological signal S in response to the sampling signal Z ₂ given from the sampling signal generating circuit 24.
Is an A / D converter for A / D conversion, and 26b and 26c are A / D converters.
Of the biological signals S digitized by the D converter 6, the timing signal Z output from the timing signal generation circuit 4
The maximum and minimum detectors for detecting the maximum and minimum values of the quantization level included in the pulse period t _{0 of 1} are respectively the maximum and minimum detectors 2b and 2c.
6b and 26c, the maximum and minimum storage circuits that store the respective biomedical signals Smax and Smin having the maximum and minimum quantization levels, and 8 are the maximum and minimum storage circuits 10b. , 10c maximum and minimum biomedical signals S
A write / read control circuit for controlling writing and reading of max and Smin. Further, 12 is a TV synchronizing signal generating circuit, 1
6 is a counter for detecting and counting the horizontal synchronizing signal included in the TV synchronizing signal output from the TV synchronizing signal generating circuit 12, 14b is a storage circuit 10b for storing the maximum value and the minimum value,
Quantization levels of the maximum and minimum biomedical signals Smax and Smin read from 10c are compared with the count value Y given from the counter 16, and the count value Y is the maximum and minimum signals Smax. , Smin is a comparison circuit that outputs a display signal when it is within the quantization level range. Reference numeral 18 denotes a one-shot circuit that inputs the display signal output from the comparator 14b and outputs a bright spot signal. The one-shot circuit 18 can adjust the pulse width of the bright spot signal that is output. Reference numeral 20 is an adder for adding the bright spot signal output from the one-shot circuit 18 in response to the display signal and the TV sync signal supplied from the TV sync signal generation circuit 12, and 22 is a TV monitor.

In the biological signal display device 1b having the above configuration, the biological signal S output from the biological signal detection circuit 2 is A / D converted by the successive A / D converter 6 according to the sampling signal Z ₂ given from the sampling signal generating circuit 24. It In this case, as shown in FIG. 3, the sampling signal Z ₂ is the timing signal Z output from the timing signal generating circuit 4.
_The frequency is higher than ₁ . Therefore, the biological signal S
Is A / D converted at a sampling rate sufficiently higher than its frequency component. The biological signal S digitized by the A / D converter 6 is commonly input to the maximum value detector 26b and the minimum value detector 26c. The maximum value and minimum value detectors 26b and 26c detect the maximum value and the minimum value of the quantization level from the biological signal S included in the pulse period t ₀ of the timing signal Z ₁ given from the timing signal generating circuit 4. The signals Smax and Smin are detected, and the detected maximum and minimum biomedical signals Smax and Smin are sent to the next maximum and minimum storage circuits 10b and 10c. Then, the maximum and minimum biological signals S obtained at each predetermined period t ₀
max and Smin are the maximum and minimum storage circuits 10b, which correspond to the write address designating signal X from the write / read control circuit 8.
It is stored at a predetermined address position of 10c. As described above, the biological signal S is A / D converted at a sampling rate of a frequency sufficiently higher than its frequency component, but the storage circuits 10b and 10c of the maximum value and the minimum value relatively slowly as in the conventional case. The maximum and minimum biomedical signals Smax and Smin are stored at the speed thus set.

Next, when data is read from the maximum and minimum storage circuits 10b and 10c, the TV sync signal output from the TV sync signal generation circuit 12 is applied to the read / write control circuit 8. The read / write control circuit 8 is responsive to the horizontal synchronizing signal included in the input TV synchronizing signal to read address designating signal X.
Is given to each of the storage circuits 10b and 10c of the maximum value and the minimum value. As a result, the maximum and minimum biometric signals Smax and Smin are read in parallel from the storage circuits 10b and 10c and sent to the comparison circuit 14b at the next stage. Since the TV synchronizing signal from the TV synchronizing signal generating circuit 12 is also given to the counter 16, the counter 16 counts the horizontal synchronizing signal included in this TV synchronizing signal and gives the count value Y to the comparing circuit 12 as well. . That is, the count value Y corresponds to the TV scanning line. The comparison circuit 14b compares the quantization level of the maximum and minimum values of the biomedical signals Smax and Smin given from the maximum and minimum storage circuits 10b and 10c with the count value Y given from the counter 16, Each biological signal S whose count value Y is the maximum value and the minimum value
When it is within the range of the quantization levels of max and Smin, a signal for sequential display is output in response to the output of the counter 16 and this signal is given to the one-shot circuit 18. One shot circuit 1
Reference numeral 8 outputs a bright spot signal each time the display signal is input from the comparator 14b, and supplies the bright spot signal to the adder 20. At this time,
The one-shot circuit 18 is provided so that the biological signals displayed on the TV monitor 22 can be visually recognized as a continuous signal.
Adjust the pulse width of the bright spot signal output by. Because if you adjust the pulse width of the bright spot signal, the TV monitor 2
This is because the width and size of the bright spots displayed on the display 2 are changed, and the biological signal, which is an aggregate of these bright spots, can be visually recognized as a further continuous one. Adder 20
Together with the bright spot signal from the one-shot circuit 18,
Since the TV sync signal 12 from the V sync signal generation circuit 12 is input, both signals are added by the adder 20 and output to the TV monitor 22. Therefore, when there are the minimum and maximum biomedical signals Smax ₁ and Smin _{1 which} are addressed and read by the read address designating signal X ₁ , the TV monitor 22 is displayed on the screen of FIG. ), The read maximum and minimum biomedical signals Sma
Interpolation data is displayed in addition to x ₁ and Smin ₁ . Therefore, the finally displayed biomedical signal is a continuous curve.

(C) Effect As described above, according to the present invention, a biological signal is displayed faithfully and in a continuous curve without missing necessary data. Therefore, not only the observation is easy, but also the reproducibility is good and the reliability is high. Moreover, since it does not require a large storage capacity, it has an excellent effect that it can be realized at low cost.

Further, by adjusting the pulse width of the bright spot signal by the one-shot circuit, the width and the size of the bright spot displayed on the TV monitor are changed, and the biological signal, which is an aggregate of these bright spots, is further continuous. It is also possible to obtain an effect that the image can be visually recognized as a thing that has been deleted.

[Brief description of drawings]

FIG. 1 shows a conventional example, and FIGS. 2 to 4 show embodiments of the present invention. FIGS. 1 and 2 are block diagrams of a biological signal display device, FIG. 3 is a waveform diagram, and FIG. FIG. 4 is an explanatory diagram showing a comparison of biosignal display examples of the conventional product and the product of the present invention. 1b ... biological signal display device, 6 ... A / D converter, 10
b, 10c ... Storage circuits for maximum and minimum values, 14b ...
Comparator circuit, 16 counter, 24 sampling signal generation circuit, 26b, 26c maximum and minimum detectors.

Claims (1)

[Claims] 1. A sampling signal generation circuit for giving a sampling signal having a frequency sufficiently larger than a frequency component of the biological signal to an A / D converter to which a biological signal such as an electrocardiogram signal or a heart sound signal is input, A detector for detecting a maximum value and a minimum value of a quantization level included in a predetermined period of a biological signal digitized by the A / D converter;
A storage circuit for storing the maximum and minimum signals detected by the detector, the quantization levels of the maximum and minimum signals read from the storage circuit, and the TV scanning line, respectively. A comparator circuit that compares a count value and outputs a display signal when the count value is within the range of the quantization level of each signal level of the maximum value and the minimum value, and an arbitrary pulse width for the display signal. And a one-shot circuit for converting the signal into a bright spot signal, and a biological signal display device capable of continuously displaying a biological signal by interpolating between the signals of the maximum value and the minimum value.